Sumo Motor Control Functions

Overview

Writing good functions for motor control are critical to writing good sumo robotics code. A motor control function can control both motor direction and speed. In this lesson, you will start with just controlling the direction of your motor. If you need to review how to write a function click here.

As you learned in a previous lesson, you can drive one of your motors with the following sort of code.

// Drive clockwise
digitalWrite(MOT1A, HIGH);
digitalWrite(MOT1B, LOW);

 // Drive counterclockwise
digitalWrite(MOT1A, LOW);
digitalWrite(MOT1B, HIGH);

There are two problems with this approach. One is that it hard to read. Two is that changing the direction of your motor requires you to write essentially the same code twice.

Imagine how much clearer your code would be if you could instead drive a motor in either direction with the following single line.

drive_motor(CLOCKWISE);
drive_motor(COUNTERCLOCKWISE);

This is the power of functions. Note that the above code assumes that there is a single function “drive_motor” that can use an argument to determine direction. Also, note that the CLOCKWISE and COUNTERCLOCKWISE are defines that you need to set at the top of your code.

Exercise:

Write a function to control just the direction of one motor. The function can be called anything you like, but you should use a name that best indicates the purpose of the function. Your function should allow you to pass one argument to change the direction of the motor. Again, if you need a reminder about how to write functions, check the link above. NOTE: Make sure to use defines for your control pins.

TEACHER CHECK ______
Write a second function to control a second motor. Make sure to use function names to accurately distinguish between the two motors.

TEACHER CHECK ______
Write a function to control both motors at the same time. Again, make sure to use function names and argument names that are appropriate to the purpose of the function.

TEACHER CHECK ______